The present invention relates generally to thermionic power conversion systems, and more specifically to modules for a nuclear energy powered thermionic reactor for space-based operation capable of providing large amounts of power in short pulses.
In the operation of a thermionic converter, heat energy is converted directly to electrical current by heating a metallic emitter to sufficiently high temperatures so that electrons escape the emitter and flow to a cooler collector. The source of heat energy for conversion to electrical current may be any of several types, including exothermic chemical reactions and the heat of nuclear fission. In order to promote efficient operation of a thermionic system to generate useful amounts of electrical power, the system must not only generate large amounts of heat required for energizing the thermionic components, but must also provide for rejection of waste heat from the cold side of the thermionics.
High power thermionic energy systems are proposed as power supplies for space-based beam or kinetic energy weapons. Those devices require substantial power, but only for short bursts. It is seen, therefore, that there is a need for a thermionic power system able to rapidily absorb very large amounts of waste heat during a high output power pulse, and then remove the absorbed waste heat energy to prepare for another pulsed output of power.
It is, therefore, a principal object of the present invention to provide an efficient high power thermionic power system particularly adaptable to high powered pulsed operations in space.
It is another object of the present invention to provide a nuclear fission powered thermionic system.
These and other objects of the present invention are achieved by the following described nuclear energy powered thermionic reactor system. A unique discovery of the present invention is the use of a heat sink material contained within the core of each reactor module to absorb the waste heat of the thermionic conversion process.
An advantage of the present invention is that the heat sink material may act as a neutron moderator, thereby reducing the amount of needed nuclear fuel.
A further advantage of the present invention is that containing the heat sink material within the reactor core eliminates any need for an intermediate heat exchanger.
Yet another advantage of the present invention is that the reactor radiation shield may be used as part of a heat sink for cooling the heat sink material in the reactor core.
The reactor, unlike open-cycle turbine generators, emits no effluents, thereby avoiding problems with thrust cancellation, contamination, and so forth. Also unlike open-cycle power supplies, the reactor is completely reusable. Further, the reactor has no moving parts, eliminating any need in a space based system for torque cancellation and reducing or eliminating vibration.